Aware of the challenge but committed to their cause, Kelly and Brent King on Monday launched the campaign to pass "Chelsea's Law."

"We must demand nothing short of swift and decisive action for all of our children," said Kelly King, the mother of slain Poway teenager Chelsea King.

Brent King comforts his wife, Kelly, as Assemblyman Nathan Fletcher talks about the introduction of Chelsea's Law. (Howard Lipin / Union-Tribune)

The grieving parents stood alongside Assemblyman Nathan Fletcher, R-San Diego, as he detailed the specifics of Chelsea's Law to target "the worst of the worst."

The legislation, Assembly Bill 1844, would adopt a one-strike rule eliminating any chance of parole for those who commit forcible sex crimes against children that involve bodily harm, torture, kidnapping or other aggravating circumstances.

Chelsea's Law would require lifetime parole for less-serious attacks, requiring the state to monitor and pay for electronic tracking of those offenders. Those on parole would be barred from visiting parks where children gather unless they have prior permission of authorities.

"The more we know about the movement of those sexually violent predators, the safer our society becomes," Brent King said.

Convicted sex offender John Albert Gardner III, 31, stands accused of killing Chelsea after she went for a run at Rancho Bernardo Community Park on Feb. 25. He has pleaded not guilty.

Gardner was off parole and was not being monitored after a past conviction on charges of beating and molesting a 13-year-old girl.

Lobbying for Chelsea's Law will continue today for the Kings and their supporters, who will rally in front of the Capitol with a thousand sunflowers, Chelsea's favorite bloom.

The biggest hurdle may be finances, given the state's deep budget crisis.

"There's no price you can put on a child's life," Kelly King said.

Fletcher's bill does not provide a price tag or indicate how the state would pay for permanent new inmates at a time when prisons are packed.

He said he will have a financing plan ready if Chelsea's Law moves to the Assembly Appropriations Committee. There it might languish until the budget negotiations progress.

The Kings meet today with Assemblyman Tom Ammiano, D-San Francisco. He chairs the Public Safety Committee, which will hear the bill April 20.

"Obviously it's a very delicate situation," Ammiano said. "We have to take a step back and be careful with this to make sure we do everything correctly. Right now, I'm open."

As is Gov. Arnold Schwarzenegger. "The governor believes those who prey upon children should face the harshest criminal penalties society can impose. He looks forward to reading Assembly member Fletcher's legislation and working with him as his bill moves forward," said Rachel Arrezola, a spokeswoman.

Fletcher's legislation is gathering support from some Democrats, a crucial step given that many GOP tough-on-crime bills have failed to secure a majority in the Democrat-dominated Legislature.

"Speaking as a mother and grandmother, you cannot put a price tag on this particular type of crime," said Assemblywoman Mary Salas, D-Chula Vista. "First and foremost, we have to protect our children."

Assemblyman Marty Block, D-San Diego, added, "Once they're convicted, in cases like these, the best thing you can do is lock them up and throw away the key."

Jill Levenson, a human services professor at Lynn University in Florida who analyzes sex-crime policy, wondered about the timing of the measure. She noted that the California Sex Offender Management Board is in the middle of examining the Gardner case.

"When these kinds of crimes happen, they are tragic and scary, and it's not surprising that people want to find ways to prevent them from happening again," Levenson said. "We need to understand how to provide better case management instead of trying to come up with another one-size-fits-all law."

Marc Renzema, a criminal justice professor at Kutztown University in Pennsylvania and an expert on GPS tracking, also was cautionary.

"I'm all for extended supervision, but not necessarily GPS for life," he said. "We don't have a clue just yet about the psychological impact or even the deterrent impact of 'forever' monitoring."

The Kings are convinced the provisions will be a deterrent.

"We have a lot of support. We have a lot of focus," Brent King said.

"We're Chelsea's parents," Kelly King said.